Method

Activity data

In past years, statistical fuel consumption data was used. But a comparison with data from German ETS (available as of 2005) exposed several inconsistencies within these statistics.

Therefore, as the fuel consumption of a compressor station depends strongly on the amount of transferred natural gas, a conversion factor was derived reflecting the relation between the fuel consumption of all compressor stations and the primary energy consumption of natural gas within Germany. Using this conversion factor, the insufficient statistical data could be replaced by much more solid estimates for the years 1990 to 2004 whereas for 2005+ the abovementioned ETS data is used.

Table: Annual natural gas consumption, [TJ]

1990

1991

1992

1993

1994

1995

1996

1997

1998

1999

19,449

20,437

20,205

21,381

21,772

23,740

26,566

25,379

25,612

25,537

2000

2001

2002

2003

2004

2005

2006

2007

2008

2009

25,324

26,706

28,689

26,988

27,125

26,778

30,453

24,581

26,215

24,485

2010

2011

2012

2013

2014

2015

2016

2017

2018

2019

21,301

21,822

Emission factors

The emission factors for pipeline comporessors have been taken from the research project "Determination and evaluation of emission factors for combustion systems in Germany for the years 1995, 2000 and 2010". A detailed description of the procedure is presented in Chapter: 1.A.1.a - Public Electricity And Heat Production.
Compressor stations, in Germany mostely gasturbines are responsible for maintaining a constant pressure in the pipline. Basically they work discontinuously which causes relatively high specific emissions. In order to reflect this point the German law allows exemptions for installations with a low level of utilization.

Table: EF used for 2011 emission estimates

Pollutant

NOx

SOx

CO

TSP

EF

[kg/TJ]

142

0.5

53

0.40

Trend discussion for Key Sources

The following diagram gives an overview of the fuel consumption in NFR 1.A.3.e

Since 1990 fuel consumption has shown an increasing overall trend. Annual fluctuations are due to the varying primary energy consumption. The maximum fuel consumption occured in 2006, the year with the so far highest German total primary energy consumption of natural gas. Thereafter, natural gas consumption decreases considerably.

Recalculations

As both AD and EFs remain unchanged compared to submission 2012, no recalculations had to be carried out.

For pollutant specific information on qualitative and quantitative impacts on 1990 and 2010 emission estimates see chapter 11. Recalculations.